About 1,000 men and women jostled each other at the Port Klang ferry terminal Monday to buy tickets on five ships bound for Indonesia's Sumatra island.

Another 1,000 lined up at a nearby hall to register for berths on two Indonesian navy ships headed for Java.

``I feel sad to be leaving, but I don't want to be whipped or jailed,'' said Mohamad Sifud, 30, who has worked illegally in Malaysian construction sites for 10 years.

``I will definitely come back legally. There is not much work back home.''

Although Malaysia faces a severe labor shortage, authorities had said there would be no more extensions to the amnesty, which began in October and was extended three times at Indonesia's request.

``Enough has been said,'' Home Minister Azmi Khalid declared. ``I hope the illegals take us seriously.''

Yet despite the threats, about half a million illegal workers are expected to stay. They will be targeted by about 300,000 police, government officials and volunteers who will fan out across Malaysia in a crackdown starting today.

Immigration officials expected 12,000 to 15,000 to go home Monday. About 400,000 have already left under the amnesty.

Those arrested in the crackdown will face punishments ranging from fines to whipping with a rattan cane and jail. They will be deported after their sentences and barred permanently from returning to the country.

Malaysian Prime Minister Abdullah Ahmad Badawi said Indonesian President Susilo Bambang Yudhoyono had written to him to seek close cooperation to resolve any problems arising from the crackdown.

``We don't want this operation to lead to any problem in the areas of cooperation between Malaysia and Indonesia,'' Abdullah said.

Rights group Suaram said the crackdown is ``unbalanced, punitive and unjust as it targets migrant workers and not employers or recruiting agents.''

Abdullah dismissed the concerns, saying officials involved ``know how to do their job.''

Malaysia and Indonesia have agreed to let illegal workers who depart before the amnesty ends return to Malaysia with proper papers. Officials in Jakarta have promised speedy processing.

Asri, a 41-year-old Indonesian married to a Malaysian, said she was torn over leaving her husband, ``but there is no other choice. I think Malaysia is very serious this time about the illegals. I hope to sort out my papers and come back to live.''

She has worked at a launderette, restaurant and boutique since 2002.

Many illegal immigrants said they will stay. ``People ask me many times if I am I not afraid of being caught and jailed,'' Alia Shukri, from a remote village near Bali, said.

``Yes, I am scared, but what choice do I have? I have three children, and there is no chance to earn a decent income to support them if I return home.''ASSOCIATED PRESS